Prazosin for treatment of nightmares related to posttraumatic stress disorder

Abstract

The efficacy of prazosin for the treatment of posttraumatic stress disorder (PTSD)-related nightmares is reviewed. PTSD is an anxiety disorder that can occur after experiencing or witnessing a life-threatening event, such as military combat, natural disasters, terrorist attacks, serious accidents, or violent personal assaults. The event that induced PTSD is often relived through nightmares or flashbacks. Sleep disturbances affect approximately 70% of patients with PTSD. Several medications have been evaluated for reducing PTSD-related nightmares, with limited success. Prazosin is a centrally and peripherally acting alpha(1)-adrenergic antagonist whose mechanism of action, favorable adverse-effect profile, and low cost make it a promising agent for the treatment of PTSD. To date, two case reports, two chart reviews, three open-label trials, and two placebo-controlled trials have been published documenting the efficacy and safety of prazosin in the treatment of PTSD-related nightmares. Therapy with prazosin resulted in a reduction in nightmares in patients with both combat- and noncombat-related trauma. A therapeutic benefit occurred with prazosin dosages as low as 1 mg daily, and suppression of nightmare symptoms occurred within one week of prazosin initiation. The most frequently reported adverse event was orthostatic hypotension. The variability in the populations studied (e.g., combat, noncombat, recent traumatic experiences) leaves additional unanswered questions that must be addressed in large, randomized, controlled trials. Prazosin appears to be a promising and well-tolerated agent for the management of PTSD-related nightmares. Further well-designed trials are warranted to establish its place in the treatment of PTSD.